1. Field of the Invention
The present invention relates to a multangular pen nib construction comprising a plurality of pen nib pieces fixed back-to-back to each other, and more particularly to such a multangular pen nib construction which is easy to manufacture and almost free from clogging when the pen is being used, and further more which is improved to prevent the ink from reverse flowing toward the ink reservoir of the pen when the pen is left with the pointed end of the pen nib pointing upward.
2. Description of the Prior Art
Fountain pens such as in usual use, which include a pen nib construction comprising a single-piece pen nib and its holder have the disadvantage that they can operate only in a certain direction. To obviate the disadvantage, a multangular pen nib construction has been provided, which comprises a plurality of (three for instance) pen nib pieces, similar to conventional pen nibs, that are fixed back-to-back to each other and held in the holder so as to make it possible to write in all directions.
An example of the prior multangular pen nib construction is shown in FIGS. 1 to 5. The multangular pen nib construction as shown in FIG. 2 has been made as follows. At first, three pen nib pieces 1, each having a slit or split 3 at a center of the pointed end and another slit or split 9 at its root, and notches 4 at both edges near the pointed end are made e.g. by stamping. Next, each of the pen nib pieces 1 is bent either in ship-bottom shape along the bending line 2 or round e.g. by pressing. Then the pen nib pieces 1 are fixed back-to-back to each other, e.g. by cementing or spot welding. As illustrated above, because the pen nib pieces are bent in ship-bottom shape, the pen nib 5 is provided with an ink channel 7 in the center thereof as shown in FIG. 3. The central top end of the pen nib 5 composes a drill-like pointed end of the pen by gathering the pointed end of each of the pen nib pieces as shown in FIG. 4. FIG. 4 is more enlarged than FIG. 3.
The pen nib 5 has three concavities 6 and three projections 12 disposed alternately along its outside. As shown in FIG. 1a, each of the pen nib pieces 1 is provided with a split 3 at its pointed end and also with notches 4 at its both edges. Therefore, the pen nib 5 is provided at its pointed end with three splits 3 and three recesses 8 formed by the notches 4 which are disposed alternately at equal angular distance as shown in FIG. 4 when it is constructed by a plurality of pen nib pieces. And, inside said ink channel 7, which extends from the root of the pen nib 5 to near the pointed end, an ink feed needle 10 consisting of some wire strands twisted together of a relatively small diameter is fixed for feeding ink from the root of pen nib 5 to the pointed end.
The pen nib 5 is fitted in a holder e.g. of a synthetic, separately made, e.g. by molding. The holder is provided with some ink feed grooves which feed the ink from the ink reservoir (or the barrel), or a cartridge to the root end of the pen nib 5, and the ink led therein through them enters into the ink channel 7 at the root end of the pen nib 5 and then flows to the pointed end of the pen nib 5.
However, the conventional multiangular pen nib construction in prior art has been found to have the following disadvantages. The pen nib pieces 1 are bent so that the ink channel 7 may have a relatively large cross-sectional area, therefore the ink feed needle 10 which usually is made thick of a plurality of wire strands twisted around each other is inserted therein to feed ink effectively through the ink channel 7. Accordingly, it is very difficult to insert such a needle into the ink channel 7 if the needle loses its tightness. And also twisted wires of the strand are easy to stick to the root edges and side walls of the ink channel 7. Consequently, there has been a problem with the manufacturing cost caused to rise because of its complex process.
In addition, the supply of the ink to the pointed end of the pen nib 5 is performed only through the ink channel 7 provided in the center thereof, and ink feed needle 10 disposed in the ink channel 7. The portion of the ink channel 7 where the ink feed needle 10 is inserted is relatively narrow compared with the ink containing portion 11 provided near the pointed end of the pen nib 5 so that while the pen is being used, the ink channel in the pen nib construction is liable to be clogged with paper fibers or dust which have been brought in and stick in or above the ink containing portion 11. Furthermore, considering the technique of a conventional multangular pen nib construction from the point of view of function or action, it is based on a technical idea to make ink flow down from the reservoir along the inside of the pen nib. In order to make ink flow more efficiently the ink feed needle 10 is used, and the ink feed needle is made of the twisted wire strands. Therefore, ink comes to be supplied relatively smoothly to the pointed end of the pen nib through the ink channel when the user writes with a pen including such a pen nib. But, on the other hand, if a pen with a cap is kept standing (a pen nib points upwards), ink which has flowed down to the pointed end of the pen flows reversely in the ink channel 7, and returns into the ink reservoir of the pen. And then, the pen nib becomes dry. Consequently, it has been a fatal disadvantage that ink does not flow out onto the paper at once when the user is about to write next time.